Risk of falls increases between cataract surgeries

NEW YORK (Reuters Health) - Older adults with cataracts
appear to double their risk of falling after surgery on their
first eye and before surgery on the second, suggests a new
study.

The finding that corrective eye surgery may - at least
temporarily - be linked to an increase in falls comes after
years of conflicting study results on the subject, researchers
write in the journal Age and Ageing.

But the topic remains important as the global population
ages and demand for cataract surgery increases. In Australia,
where the study was conducted, cataract surgeries tripled over
the past two decades.

"This study tells us that timing of cataract surgeries is
very important," Dr. Ediriweera Desapriya of the University of
British Columbia in Vancouver, Canada, told Reuters Health.

Desapriya has researched falls in older adults at the Center
for Clinical Epidemiological and Evaluation Research, but wasn't
involved in the new study.

"In the past, you didn't really want to get both eye
surgeries done at the same time," Desapriya said. That was in
case of problems like infection or swelling. "But now the
technology has improved and complications occur less often," he
said.

For their study, Lynn Meuleners of Curtin University and her
team in Perth looked back through detailed electronic health
records from Western Australia's hospitals and its death
registry.

Between 2001 and 2008, nearly 28,400 older adults in the
region had cataract surgery on both eyes. The researchers found
1,094 of them also took a fall serious enough to warrant a
hospital visit during that period.

People waited an average of 10 months between eye surgeries.
Compared to the two-year period before any cataract surgery,
their chance of falling doubled between procedures.

In the two years after surgery on their second eye, people's
fall risk was 34 percent higher than before their first surgery.
The risk of falling also rose with age.

Most people who fell were older than 80, women, city
dwellers and were not married.

"It's a well-conducted study," said Stephen Lord, a senior
principal research fellow with Neuroscience Research Australia
in Sydney. Lord was not involved with the current study, but
researches balance and falls among older adults.

"In the intervening time between surgeries, you have a
person with two eyes that are no longer equal and this can lead
to various effects," Lord said - like on visual sharpness and
depth of field.

"For these things, we need two eyes working together," he
told Reuters Health.

However, at least one previous randomized controlled trial -
medicine's gold standard for research - found people had fewer
falls after cataract surgery, Lord said.

Based on this study, doctors could warn patients to be extra
cautious after having surgery on their first eye, Desapriya
said.

"It is also important to encourage patients to have a second
eye cataract surgery early," Desapriya said. "Otherwise, eyes
continue to function monocularly (with just one eye) and
patients lose their depth perception."

The new research cannot point to cataract surgery as the
primary cause of the falls - it only suggests they are linked.

The researchers said a limitation of their study is a lack
of knowledge about people's lifestyles, including their living
situations, and co-existing eye conditions, both of which could
strongly influence fall risk.

They also did not look at falls among people who had not
undergone cataract surgery. Such comparisons are helpful when
considering changes in risk.

"The aging population is growing rapidly in the U.S. and
Canada," Desapriya said. "And this surgery is becoming a very
common clinical procedure."

According to the National Eye Institute, more than half of
all Americans have a cataract or have had cataract surgery by
the time they're 80.

Lord compared cataract surgery to a major change in
prescription eyeglasses: in both cases, the brain needs time to
adjust to the changes in vision.

But patients and doctors should not shy away from cataract
operations, Lord said.

"The last thing we want to have happen is to prevent people
from receiving cataract surgery," Lord said. "This surgery has
many benefits, such as improving quality of life, increasing a
person's participation in the community and even preventing
falls in the longer term."

"It just seems that, in the short term, there may be a
problem while people adjust to their new vision," he said.

SOURCE: http://bit.ly/1a6GaEY Age and Ageing, online
November 4, 2013.